Planetary gear reducer electric drive axle and electric vehicle

Abstract

The present invention discloses a planetary gear reducer electric drive axle and an electric vehicle. The planetary gear reducer electric drive axle includes a planetary wheel carrier assembly, including a carrier body and a planetary shaft fixed to the carrier body, the carrier body has a power input side and a power output side; a connecting component, which is arranged on the power input side of the carrier body; and a motor assembly, the motor assembly includes a motor body, a mounting seat is arranged on the motor body, the carrier body is rotatably connected to the mounting seat through the connecting component, and the connecting component and the mounting seat form a limited fit in the axial direction of the planetary gear reducer electric drive axle.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicles, and in particular to an electric drive axle with a planetary gear reducer and an electric vehicle. Background Art

[0002] The electric drive axle of an electric vehicle consists of a motor and a reducer. The reducer is used to reduce the power output of the motor, increase the torque, and then output it to the outside. The reducer structure can be divided into fixed-axis reducers and rotating-axis reducers. The rotating-axis reducer is equipped with a planetary gear structure.

[0003] In related technologies, a reducer is equipped with a planetary gear mechanism, including a sun gear, planetary gears, a planetary carrier connected to the planetary gears, and an internal gear ring. The internal gear ring is fixedly connected to the motor, and the sun gear and planetary carrier respectively complete the power input and output. In this solution, the planetary carrier is not fixed in the axial direction, making it prone to axial movement. This movement is prone to noise, seriously affecting the NVH (Noise, Vibration, Harshness) performance of electric vehicles. Summary of the Invention

[0004] The present invention aims to provide a new technical solution for a planetary gear reducer electric drive axle and an electric vehicle.

[0005] In the first aspect, the present invention provides a planetary gear reducer electric drive axle, including a planetary wheel carrier assembly, including a carrier body and a planetary shaft fixed to the carrier body, the carrier body having a power input side and a power output side; a connecting component, arranged on the power input side of the carrier body; and a motor assembly, the motor assembly including a motor body, a mounting seat being arranged on the motor body, the carrier body being rotatably connected to the mounting seat via the connecting component, and the connecting component and the mounting seat forming a limited fit in the axial direction of the planetary gear reducer electric drive axle.

[0006] The connecting assembly rotatably connects the planetary carrier assembly to the motor body, without affecting the planetary carrier's power output function. It also forms an axial limiter between the planetary carrier assembly and the motor body, effectively preventing axial movement and noise from the planetary carrier assembly, thereby improving the NVH performance of electric vehicles.

[0007] Optionally, the connecting assembly includes a wheel carrier bearing and a locking nut, the mounting seat is constructed with an annular boss, the wheel carrier bearing is sleeved on the annular boss, the locking nut axially presses the inner ring of the wheel carrier bearing against the axial surface of the annular boss, and the outer ring of the wheel carrier bearing is fixed to the frame body.

[0008] Optionally, a wheel frame shaft hole and a wheel frame retaining ring groove are formed on the inner wall of the power input side of the frame body, a wheel frame retaining ring is embedded in the wheel frame retaining ring groove, the wheel frame retaining ring groove is axially opposite to the table surface of the wheel frame shaft hole, and the outer ring of the wheel frame bearing is axially clamped between the table surface of the wheel frame shaft hole and the wheel frame retaining ring.

[0009] Optionally, a locking boss is formed on the inner ring of the annular boss and protrudes axially toward the output side of the frame body. The locking nut is sleeved on the locking boss and threadedly connected to the locking boss.

[0010] Optionally, the locking nut axially presses the inner ring of the wheel carrier bearing against the axial surface of the annular boss.

[0011] Optionally, a process hole is formed in the locking nut, and the process hole is radially closer to the outer ring edge of the locking nut.

[0012] Optionally, the frame body forms a cavity, and both ends of the planetary shaft are axially fixed to the inner wall of the cavity.

[0013] Optionally, the motor body includes a motor end cover, the motor shaft extends from the motor end cover, and the annular boss located on the motor end cover is coaxially arranged with the motor shaft.

[0014] Optionally, an inner gear ring is further included, and the planetary wheel carrier assembly is located radially inward of the inner gear ring;

[0015] The planetary shaft is rotatably connected to a planetary gear, the planetary gear is meshed with the inner ring gear and the sun gear, and the inner ring gear is fixed to the motor end cover.

[0016] In a second aspect, the present invention provides an electric vehicle comprising the above-mentioned planetary gear reducer electric drive axle.

[0017] Other features and advantages of the present specification will become apparent from the following detailed description of exemplary embodiments of the present specification with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the specification and, together with the description, serve to explain the principles of the specification.

[0019] Figure 1 is a cross-sectional view of an electric drive axle of a planetary gear reducer according to an embodiment of the present invention;

[0020] Figure 2 1. It is a partial exploded schematic diagram of the electric drive axle of the planetary gear reducer according to an embodiment of the present invention;

[0021] Figure 31 is a cross-sectional view of a carrier body of a planetary wheel carrier assembly of an electric drive axle of a planetary gear reducer according to an embodiment of the present invention;

[0022] Figure 4 yes Figure 1 A partial enlarged schematic diagram;

[0023] Figure 5 is a front view of the first flange structure of the planetary wheel carrier assembly in an embodiment of the present invention;

[0024] Figure 6 is a front view of the second flange structure of the planetary wheel carrier assembly in an embodiment of the present invention;

[0025] Figure 7 This is a transmission principle diagram of the electric drive axle of the planetary gear reducer in an embodiment of the present invention.

[0026] Description of reference numerals:

[0027] 100, reducer; 200, motor assembly; 1, first-stage reduction mechanism; 11, inner ring gear; 11-1, first-stage inner ring gear; 12, sun gear; 2, second-stage reduction mechanism; 21, second-stage sun gear; 3, frame body; 31, first flange structure; 32, second flange structure; 33, connecting plate; 34, wheel frame shaft hole; 36, wheel frame retaining ring groove; 37, cavity; 41, first planetary shaft hole; 42, second planetary shaft hole; 43, row Planet shaft retaining ring; 44, planetary gear; 44-1, first-stage planetary gear; 45, planetary bearing; 46, bearing retaining ring; 47, washer; 48, planetary shaft; 5, motor end cover; 50, mounting seat; 51, motor shaft; 52, annular boss; 53, locking boss; 54, connecting screw hole; 6, wheel carrier bearing; 61, wheel carrier retaining ring; 7, locking nut; 71, bolt through hole; 72, process hole; 8, locking bolt; 9, planetary gear assembly. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0029] According to one embodiment of the present invention, a planetary gear reducer electric drive axle is provided, including a planetary gear reducer. For example, the planetary gear reducer 100 can be applied to a coaxial electric drive axle. The reducer 100 can also be applied to other types of electric drive axles, without specific limitation herein.

[0030] like Figure 7 As shown, Figure 7This is a transmission schematic diagram of the primary reduction mechanism of the reducer of the present invention. For ease of description, the primary reduction mechanism 1 shown in the figure includes the primary sun gear 12, the primary ring gear 11-1, the primary planetary gear carrier assembly 3-1, and the primary planetary gear assembly 44-1. The components of the secondary reduction mechanism 2 are the same as those of the primary reduction mechanism 1, including the secondary sun gear 21.

[0031] See also Figure 7 The primary sun gear 12 is connected to the motor shaft 51 and is driven to rotate by the motor shaft 51. The primary ring gear 11-1 is a fixed end. The primary planetary gear assembly 44-1 meshes with the primary sun gear 12 and the primary ring gear 11-1. Under the action of the primary sun gear 12 and the primary ring gear 11-1, it revolves along the central axis of the primary sun gear 12. As the primary planetary gear assembly 44-1 revolves, it drives the primary planetary wheel carrier assembly 3-1 connected to it to rotate, transmitting power to the secondary reduction mechanism 2 through the primary planetary wheel carrier assembly 3-1. Specifically, the primary planetary wheel carrier assembly 3-1 transmits power to the secondary sun gear 21. The power transmission process of the secondary reduction mechanism 2 is the same as that of the primary reduction mechanism 1 and will not be explained again.

[0032] by Figure 1 、 Figure 2 Right now Figure 4 As shown, the planetary gear reducer 100 includes a sun gear 12, an inner ring gear 11, a planetary wheel carrier assembly and a planetary wheel assembly 9. The planetary wheel assembly 9 includes planetary gears 44, planetary shafts 48, planetary bearings 45 and limiting components therebetween.

[0033] The planetary gear carrier assembly includes a carrier body 3. The planetary shaft 48 is fixed to the carrier body 3. The carrier body 3 has a power input side and a power output side. The power input side of the carrier body 3 is closer to the motor assembly 200 in the axial direction of the reducer 100.

[0034] The central axis position of the planetary gear assembly 9 is relatively fixed, and the planetary gear assembly 9 is engaged with the sun gear 12 and the inner ring gear 11 at the same time, thereby driving the frame body 3 of the planetary gear carrier assembly to rotate, so as to transmit power to the secondary reduction mechanism 2 through the power output side.

[0035] like Figure 2 、 Figure 4 and Figure 5 As shown, the output side of the carrier body 3 is fixedly connected to the secondary sun gear 21. For example, the output side of the carrier body 3 and the secondary sun gear 21 are connected by interference fastening, or they can be connected by welding, spline fastening, or other fixed methods. In this way, the carrier body 3 transmits the power of the primary reduction mechanism 1 to the secondary reduction mechanism.

[0036] In one example, in order to increase the structural rigidity of the planetary wheel carrier assembly, the defect of the existing flange structure planetary wheel carrier assembly that is easily deformed in the working state is avoided, and the early damage of the reduction mechanism caused by the deformation of the planetary wheel carrier assembly is overcome.

[0037] like Figure 3 As shown, the frame body 3 is a cage-shaped frame structure. The cage-shaped frame structure includes a first flange structure 31 located on the power input side and a second flange structure 32 located on the power output side. The flange of the first flange structure 31 protrudes toward the direction close to the motor body, and the flange of the second flange structure 32 protrudes away from the motor body and is fixedly connected to the secondary sun gear 21. A plurality of connecting plates 33 are arranged circumferentially around the first flange structure 31 and the second flange structure 32 to jointly enclose a cavity 37 of the cage-shaped frame structure. Both ends of the planetary shaft 48 are axially fixed to the inner wall of the cage-shaped cavity 37.

[0038] Specifically, first and second planetary shaft holes 41, 42 are defined at axially opposing positions of the first and second flange structures 31, 32. The end of the planetary shaft 48, proximal to the first flange structure 31, forms an axial stop with the stepped surface of the first planetary shaft hole 41. The other end of the planetary shaft 48 forms a stop with a planetary shaft retaining ring 43 embedded in the second planetary shaft hole 42 of the second flange structure 32. The radial dimensions of the first and second planetary shaft holes 41, 42 match the radial dimensions of the corresponding connection points of the planetary shaft 48.

[0039] See also Figure 2 and Figure 4 The planetary shaft 48 is rotatably connected to the planetary gear 44. The planetary gear 44 and the planetary shaft 48 are rotatably connected via the planetary bearing 45.

[0040] For example, Figure 2 and Figure 4 As shown, two sets of planetary bearings 45 can be provided. A stepped structure is constructed in the inner bore of the planetary gear 44. The planetary bearings 45 are secured by the stepped structure and a bearing retaining ring 46 disposed therein. The two sets of planetary bearings 45 are sleeved around the planetary shaft 48, enabling the planetary gear 44 to rotate about the planetary shaft 48. Furthermore, washers 47 are provided on each axial end face of the planetary bearings 45 to protect the planetary bearings 45 and facilitate the installation and support of the planetary gear 44 and the planetary bearings 45.

[0041] For example, see Figure 4The primary reduction mechanism 1 further includes an inner ring gear 11. The planetary gear carrier assembly is located radially inward of the inner ring gear 11. The radially outer portions of the planetary gears 44 mesh with the inner ring gear 11. The inner ring gear 11 is fixed to the motor end cover 5. The fixed connection between the inner ring gear 11 and the motor end cover 5 ensures that the primary reduction mechanism 1 is positioned radially relative to the motor body of the reducer 100.

[0042] like Figure 1 、 Figure 2 and Figure 4 As shown, motor assembly 200 includes a motor body. The motor body includes a motor end cap 5, on which a mounting base 50 is configured. Motor assembly 200 includes a motor shaft 51. Motor shaft 51 extends through the power input side of frame body 3 into cavity 37 and is connected to sun gear 12. Rotating sun gear 12 thereby rotates the planetary gear assembly 9 meshing with sun gear 12.

[0043] For example, the electric drive axle of the planetary gear reducer also includes a connecting assembly. The frame body 3 is rotatably connected to the mounting seat 50 through the connecting assembly. That is, the flange flange of the first flange structure 31 is rotatably connected to the mounting seat 50. When the frame body 3 rotates relative to the motor body driven by the planetary gear 44, the first flange structure 31 and the second flange structure 32 rotate together relative to the motor body. The connecting assembly and the mounting seat 50 form a limited fit in the axial direction of the reducer 100, that is, the first flange structure 31 forms a limited fit in the axial direction with the mounting seat 50 through the connecting assembly. The frame body 3 has no degree of freedom in the axial direction relative to the motor body. The frame body 3 can only rotate in the circumferential direction relative to the motor body.

[0044] This method allows the planetary gear carrier assembly to rotate freely relative to the motor body, outputting power to the next-stage reduction mechanism through the carrier body 3. It also avoids the need for axial centering using the inner ring gear 11, overcoming the problem of axial movement of the planetary gear carrier assembly, thereby improving the NVH (Noise, Vibration, Harshness) performance of electric vehicles. Furthermore, it reduces the risk of excessive stress and deformation of the inner ring gear 11 caused by axial centering using the inner ring gear 11.

[0045] In one embodiment, see Figure 2 as well as Figure 4, the connecting assembly includes a wheel carrier bearing 6 and a locking nut 7. The locking nut 7 is annular, and the motor shaft 51 extends from the motor end cover 5. The mounting seat 50 is constructed with an annular boss 52, and the annular boss 52 is arranged on the motor end cover 5. The annular boss 52 protrudes axially toward the direction close to the reducer 100. The annular boss 52 is coaxially arranged with the motor shaft 51. The wheel carrier bearing 6 is sleeved on the annular boss 52, and the surface of the locking nut 7 axially presses the inner ring of the wheel carrier bearing 6 against the axial table surface of the annular boss 52, and the outer ring of the wheel carrier bearing 6 is fixed to the frame body 3.

[0046] For example, Figure 2 and Figure 4 As shown, the locking nut 7 is connected to the motor's end cap. It is axially located on the side of the wheel carrier bearing 6 closest to the output side of the frame body 3 and presses against the inner ring end face of the wheel carrier bearing 6 to axially hold the wheel carrier bearing 6 against the surface of the annular boss 52. The wheel carrier bearing 6 is, for example, a ball bearing having an inner ring, an outer ring, and balls positioned between the inner and outer rings. A retainer may also be provided between the inner and outer rings.

[0047] The side surface of the annular boss 52 is fitted with the inner ring of the wheel carrier bearing 6. During the assembly process, the locking nut 7 is first placed in a set position, and then the wheel carrier bearing 6 is installed.

[0048] For example, see Figure 4 In order to achieve the connection between the locking nut 7 and the annular boss 52, the inner ring of the wheel carrier bearing 6 extends axially toward the output side to form a locking boss 53, and the motor shaft 51 extends outward from the center of the locking boss 53. The locking boss 53 is an annular structure, and the motor shaft 51 extends from the position where the central axis of the locking boss 53 is located. The locking nut 7 is sleeved on the locking boss 53. The inner ring of the locking nut 7 and the outer surface of the locking boss 53 are provided with matching threads. Thus, the locking nut 7 can be threadedly connected to the locking boss 53. The part of the axial end face of the locking nut 7 close to the inner hole is in contact with the end face of the annular boss 52, and the part close to the outer ring of the locking nut 7 is in contact with the inner ring end face of the wheel carrier bearing 6 sleeved on the annular boss 52. It is understandable that the locking nut 7 may not fit in the axial direction with the end face of the annular boss 52 , so that the locking nut 7 can axially press the inner ring of the wheel carrier bearing 6 against the axial surface of the annular boss 52 .

[0049] In this manner, the locking nut 7 and the annular boss 52 cooperate to secure the inner ring of the wheel carrier bearing 6 to the motor body, while the outer ring of the wheel carrier bearing 6 is connected to the frame body 3. Thus, the frame body 3 can be removably secured to the motor end cover 5 through the cooperation between the locking nut 7 and the locking boss 53. Clamped by the locking nut 7 and the annular boss 52, the wheel carrier bearing 6 is axially limited relative to the motor body, thereby preventing axial movement of the planetary wheel carrier assembly, reducing stress on the inner ring gear 11, and preventing deformation of the inner ring gear 11 and the frame body 3. At the same time, the wheel carrier bearing 6 maintains rotational freedom. The planetary wheel carrier assembly can freely rotate relative to the motor assembly 200 to output power.

[0050] For example, Figure 2 and Figure 6 As shown, a connecting screw hole 54 is provided at the position where the annular boss 52 and the locking nut 7 meet. A bolt through hole 71 is provided in the locking nut 7, and the connecting screw hole 54 is provided with a thread. A locking bolt 8 passes through the bolt through hole 71 and connects with the connecting screw hole 54 to secure the locking nut 9 to the motor end cover 5.

[0051] By opening a connecting screw hole 54 on the surface of the annular boss 52 of the motor end cover 5, the locking nut 7 is prevented from loosening by using a locking bolt 8 to prevent the locking nut 7 from loosening after being threadedly connected to the mounting seat 50.

[0052] For example, the locking nut 7 further defines a process hole 72, which is radially closer to the outer ring edge of the locking nut 7. Figure 2 and Figure 6 The bolt holes 71 are spaced apart along the circumference of the planetary wheel carrier assembly. The process holes 72 are staggered with the bolt holes 71 along the circumference. The staggered arrangement of the process holes 72 and the bolt holes 71 further saves space. It is understood that the process holes 72 and the bolt holes 71 can also be arranged side by side along the circumference.

[0053] By providing the process hole 72 , it is possible to facilitate the positioning and tightening operation of the tightening tool through the process hole 72 when tightening the lock nut 7 .

[0054] In this way, the locking nut 7 realizes a detachable connection between the planetary carrier assembly and the motor assembly 200 .

[0055] In addition, by providing a plurality of bolt through holes 71 and process holes 72 , the operating angle during installation is increased, so that the locking bolt 8 can be used to lock the locking nut 7 at different angles.

[0056] In one example, see Figure 3 as well as Figure 4 and Figure 5To secure the outer ring of the wheel carrier bearing 6 to the frame body 3, a wheel carrier shaft hole 34 and a wheel carrier retaining ring groove 36 are defined along the inner wall of the frame body 3 on the power input side. A wheel carrier retaining ring 61 is embedded within the wheel carrier retaining ring groove 36. The wheel carrier retaining ring groove 36 and the table surface of the wheel carrier shaft hole 34 are axially opposed. The outer ring of the wheel carrier bearing 6 is axially clamped between the stepped surface of the wheel carrier shaft hole 34 and the wheel carrier retaining ring 61, thereby forming a connection between the wheel carrier bearing 6 and the frame body 3 and providing axial positioning.

[0057] In this way, by fixing the inner ring of the wheel carrier bearing 6 to the motor body and the outer ring to the carrier body 3, the planetary wheel carrier assembly rotates relative to the motor assembly 200, while simultaneously limiting the position of the planetary wheel carrier assembly in the axial direction. In this way, the planetary wheel carrier assembly is limited in the radial direction.

[0058] In one example, the reduction ratio of the primary reduction mechanism of the electric drive axle in the present invention is 3.93, the reduction ratio of the secondary reduction mechanism is 3.75, and the total reduction ratio can reach 14.74.

[0059] In another embodiment of the present invention, an electric vehicle is provided, comprising the aforementioned electric drive axle. The motor body and the planetary wheel carrier assembly of the electric drive axle are rotatably connected, and the connecting assembly forms an axial limit, thereby improving the NVH performance of the electric vehicle.

[0060] In addition, the detachable connection between the locking nut 9 and the motor end cover 5 facilitates the modular assembly of the electric drive axle of the electric vehicle and reduces the difficulty of mass production of the coaxial electric drive axle.

[0061] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A planetary gear reducer electric drive axle, characterized in that: include: A planetary wheel carrier assembly comprises a carrier body (3) and a planetary shaft (48) fixed to the carrier body (3), wherein the carrier body (3) has a power input side and a power output side; A connecting assembly is provided on the power input side of the frame body (3); as well as A motor assembly (200), the motor assembly (200) comprising a motor body, a mounting seat (50) being provided on the motor body, the frame body (3) being rotatably connected to the mounting seat (50) via the connecting assembly, the connecting assembly and the mounting seat (50) forming a limited fit in the axial direction of the electric drive axle of the planetary gear reducer; The connecting assembly includes a wheel carrier bearing (6) and a locking nut (7), the mounting seat (50) is constructed with an annular boss (52), the wheel carrier bearing (6) is sleeved on the annular boss (52), the locking nut (7) axially presses the inner ring of the wheel carrier bearing (6) against the axial surface of the annular boss (52), and the outer ring of the wheel carrier bearing (6) is fixed to the frame body (3); A locking boss (53) is formed on the inner ring of the annular boss (52) and protrudes axially toward the output side of the frame body (3). The locking nut (7) is sleeved on the locking boss (53) and is threadedly connected to the locking boss (53).

2. The planetary gear reducer electric drive axle according to claim 1, characterized in that: The inner wall of the power input side of the frame body (3) is provided with a wheel frame shaft hole (34) and a wheel frame retaining ring groove (36), a wheel frame retaining ring (61) is embedded in the wheel frame retaining ring groove (36), the wheel frame retaining ring groove (36) is axially opposite to the table surface of the wheel frame shaft hole (34), and the outer ring of the wheel frame bearing (6) is axially clamped between the table surface of the wheel frame shaft hole (34) and the wheel frame retaining ring (61).

3. The planetary gear reducer electric drive axle according to claim 1, characterized in that: The locking nut (7) axially presses the inner ring of the wheel carrier bearing (6) against the axial surface of the annular boss (52).

4. The planetary gear reducer electric drive axle according to claim 3, characterized in that: The locking nut (7) is provided with a process hole (72), and the process hole (72) is closer to the outer ring edge of the locking nut (7) in the radial direction.

5. The planetary gear reducer electric drive axle according to any one of claims 1 to 4, characterized in that: The frame body (3) encloses a cavity (37), and both ends of the planetary shaft (48) are axially fixed to the inner wall of the cavity (37).

6. The planetary gear reducer electric drive axle according to claim 5, characterized in that: The motor body comprises a motor end cover (5), a motor shaft (51) extends from the motor end cover (5), and an annular boss (52) located on the motor end cover (5) is coaxially arranged with the motor shaft (51).

7. The planetary gear reducer electric drive axle according to claim 6, characterized in that: It also includes an inner gear ring (11), and the planetary wheel carrier assembly is located radially inward of the inner gear ring (11); The planetary shaft (48) is rotatably connected to a planetary gear (44), the planetary gear (44) is meshed with the inner gear ring (11) and the sun gear (12), and the inner gear ring (11) is fixed to the motor end cover (5).

8. An electric vehicle, characterized in that: A planetary gear reducer electric drive axle comprising the planetary gear reducer electric drive axle according to any one of claims 1 to 7.

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